1. Field of the Invention
The present invention relates to toner that is used in development by printers, electronic-photographic apparatus and a toner manufacturing method.
2. Description of the Related Art
In electro-photographic apparatus or electrostatic recording apparatus, for making an electrostatic latent image formed on a photo-conductive drum or an electrostatic image holder that is made of dielectric into a visible image, a developing device is used. In this developing device, it is generally known that the fog of images is prevented and scattering of toner can be improved by sufficiently holding an amount of electric charge of toner contained in developer that is used for the development of an electrostatic latent image. As a definite method for retaining a sufficient amount of electric charge in toners, a Charge Control Agent (hereinafter, abbreviated to CCA) comprising such metallic complexes as zirconium complex, chromium complex, zinc complex, boron complex, iron complex, etc. is so far contained in toner mother particles.
However, conventional toner mother particles containing the CCA comprising the above-mentioned metallic complexes is able to secure a sufficient amount of electric charge by the CCA but the startup of charge is worse depending on using conditions; that is, a time is required to fully charge toner. Therefore, the quality of images may drop for the image fog when toner is initially used. Further, the device may be contaminated by scattering toner.
On the other hand, with the downsizing of apparatus and the full color development of images, the downsizing of a developing device is also demanded in recent years and the necessity for a developing device with the reduced capacity for containing developer increases as an inevitable consequence. Further, in a full color electronic-photographing apparatus, as the printing rate becomes higher than monochrome electronic-photographing apparatus, a probability for using toner immediately after supplied for the development in a developing device is increasing. As a result of reduced capacity of a developing device for storing developer and increase in the printing rate, it becomes necessary to accelerating the startup of the charging of toner mother particles more than before.
An object of the present invention is to provide toner that has a quick charging startup and is able to obtain a satisfactory amount of electric charge even at the initial stage of toner irrespective of a developer storage capacity of a developing device or increase in a printing rate and a clear and good image even in a full colored image without causing the image fog and the toner scattering to surroundings.
According to the present invention, toner comprising toner mother particles in a mean particle size A [xcexcm] containing a metallic complex; and zinc stearate in a mean particle size 2-A [xcexcm], externally added to the toner mother particles by 0.05-5.0% is provided.
Further, according to the present invention, a method for manufacturing toner is provided. The method comprises the steps of preparing toner mother particles containing a metallic complex; and externally adding zinc stearate to the toner mother particles by 0.05-5.0%.